In exchange for allowing mining to proceed near Fort Meade in Hardee County, Mosaic Fertilizer will buy a 4,400-acre ranch and donate it for use as a new state park.

In addition, the company has agreed to pull back its mining from the Peace River, which supplies water to people in Sarasota and Charlotte counties. The company will preserve 400 acres of land between the southwest mine border and the river, and also preserve about 70 acres of a type of wetlands known as bayheads that are difficult to re-create or restore.

"This is a great outcome," said Mosaic public affairs manager Russell Schweiss. "We're encouraged we were able to reach a reasonable agreement."

For Mosaic, this means a green light for a long-sought expansion of a mine on the border of Hardee and Polk counties that employs 225 people and would produce 30 percent of the rock that its Florida plants process into diammonium phosphate fertilizer, known as DAP. Without the new mine, Mosaic might have to import rock from Morocco or Peru at a higher cost to keep its fertilizer plants running at full capacity.

Environmental groups hailed the settlement as a major victory.

"This is much better protection for the Peace River than if we had not sued in the first place," Sierra Club spokeswoman Beverly Griffiths said.

Mosaic's original plan for the 7,687-acre mine expansion called for destroying 534 acres of wetlands, 26 acres of open water and more than 10 miles of streams associated with the headwaters of the Peace River.

The U.S. Army Corps of Engineers approved a permit for the wetlands destruction.

To make up for the environmental damage, the corps required Mosaic to create about 480 acres of new wetlands — something scientists say is often difficult, if not impossible.

The corps' own rules require looking for less environmentally damaging alternatives when a project does not have to be built in wetlands.

If the agency relies on the applicant to do that analysis, then the corps must double-check the work.

But according to the U.S. Environmental Protection Agency, Mosaic and the corps failed to meet their responsibilities.

For example, the EPA said, Mosaic should have considered a smaller mine that wouldn't destroy so many wetlands. And the corps didn't independently verify the company's findings.

So in 2010 three environmental groups — the Sierra Club, ManaSota-88, and People for Protecting the Peace River — sued to block it. They cited the corps' own findings that phosphate mining had already led to the loss of 343 miles of streams and 136,000 acres of wetlands in the Peace River region.

Using the EPA findings, they persuaded U.S. District Judge Henry Lee Adams to issue a temporary injunction to halt the mining of the Fort Meade expansion.

Mosaic officials said they would be forced to close the mine and notified its workers they faced layoffs in 60 days unless the judge lifted the order. Instead, Adams indefinitely continued the ban.

In November 2010, though, the two sides cut a deal to allow mining on about 200 acres.

Meanwhile, Mosaic's attention turned to the Peaceful Head Ranch in DeSoto County, at the confluence of the Peace and Horse Creek. Florida officials have long wanted to acquire the property, in part because its 10 miles of riverfront "is largely pristine with a wetlands corridor consisting mostly of sabal palms, cypress, and live oak," according to a state report on the land.

However, with the Florida Forever land-buying fund cutbacks in recent years, the state could not afford it. So when the property came up for auction in December, Mosaic bought it for $10 million. That's the land it will now donate to the state for use as a park under the settlement.

The Fort Meade mine settlement does not affect the legal challenge by environmental groups to another proposed mine expansion in Manatee County.